docs: add security audits and Plan 4 for blocker fixes

- 2026-04-18 initial audit verification (all fixed except H8) - 2026-05-01 audit with 8 new findings (B1-B4, I1-I6) - Plan 4: Security Blocker Fixes implementation plan Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-05-02 00:42:17 -04:00
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+# Verification: 2026-04-18 Initial Security Audit
+
+**Verified by:** Claude Opus 4.5  
+**Date:** 2026-05-01  
+**Methodology:** Code inspection of referenced file paths and line numbers
+
+---
+
+## Summary
+
+| Finding | File Exists | Lines Match Current | Vulnerability Status | Confidence |
+|---------|-------------|---------------------|---------------------|------------|
+| C1 - Setup web-accessible | ✅ | ❌ refactored | **FIXED** | 10/10 |
+| C2 - Message router trusts all | ✅ | ❌ refactored | **FIXED** | 10/10 |
+| C3 - Capture innerHTML XSS | ✅ | ❌ refactored | **FIXED** | 10/10 |
+| C4 - Autofill no origin check | ✅ | ❌ refactored | **FIXED** | 10/10 |
+| H1 - KDF unprefixed concat | ✅ | ❌ refactored | **FIXED** | 10/10 |
+| H2 - Master key not zeroized | ✅ | ❌ refactored | **FIXED** | 9/10 |
+| H3 - Passphrase gate cosmetic | ✅ | ❌ refactored | **FIXED** | 10/10 |
+| H4 - Git shells out unsafely | ✅ | ❌ refactored | **FIXED** | 10/10 |
+| H5 - WASM Math.random() | ✅ | ❌ refactored | **FIXED** | 10/10 |
+| H6 - Modulo bias | ✅ | ❌ refactored | **FIXED** | 10/10 |
+| H7 - rpassword outdated | ✅ | ✅ | **FIXED** | 10/10 |
+| H8 - Storage plaintext | ✅ | ⚠️ partial | **ACKNOWLEDGED** | 8/10 |
+
+**Verdict:** All CRITICAL and HIGH findings except H8 have been remediated. The codebase has been significantly refactored since this audit, making line number references obsolete but confirming fixes were applied.
+
+---
+
+## CRITICAL Findings
+
+### C1: Setup wizard web-accessible
+
+- **Original claim:** `web_accessible_resources` with `matches: ["<all_urls>"]` allows any website to inject vault config.
+- **Current state:** `extension/manifest.json` line 38 shows `"web_accessible_resources": []` (empty array).
+- **Router validation:** `router/index.ts` lines 29-71 verify sender origins (`isPopup`, `isSetup`, `isContent`) and return `unauthorized_sender` for invalid callers.
+- **Status:** ✅ **FIXED**
+
+### C2: Service-worker trusts every message
+
+- **Original claim:** `index.ts:116-441` ignores `_sender` and trusts all messages.
+- **Current state:** `service-worker/index.ts` is now 100 lines; message handling delegated to modular router.
+- **Router checks:**
+  - `sender.frameId === 0` for content scripts (line 42)
+  - `sender.id === chrome.runtime.id` (line 43)
+  - Returns `{ ok: false, error: 'unauthorized_sender' }` for invalid senders
+- **Status:** ✅ **FIXED**
+
+### C3: Capture prompt innerHTML injection
+
+- **Original claim:** `capture.ts:172-191` uses innerHTML with attacker-controlled strings in page DOM.
+- **Current state:** 
+  - Uses `createShadowHost()` (line 128) for closed Shadow DOM
+  - Builds DOM via `document.createElement` + `.textContent =` (lines 143-216)
+  - File header (lines 6-9) documents this pattern
+- **Status:** ✅ **FIXED**
+
+### C4: Autofill has no origin check
+
+- **Original claim:** `get_autofill_candidates` accepts URL from message payload; `get_credentials` returns any entry by ID.
+- **Current state in `content-callable.ts`:**
+  - Line 25: `const senderHost = safeHostname(sender.tab?.url ?? '')` — uses sender tab, not message
+  - Line 44: `if (!itemHost || itemHost !== senderHost) return { ok: false, error: 'origin_mismatch' }`
+  - Lines 46-51: TOFU origin-ack check before returning credentials
+- **Status:** ✅ **FIXED**
+
+---
+
+## HIGH Findings
+
+### H1: Argon2id unprefixed concatenation
+
+- **Original claim:** `crypto.rs:225-227` has `password = passphrase || image_secret` without length prefix.
+- **Current state at `crypto.rs:229-236`:**
+  ```rust
+  let mut password = Zeroizing::new(Vec::with_capacity(8 + nfc_passphrase.len() + 8 + 32));
+  password.extend_from_slice(&(nfc_passphrase.len() as u64).to_be_bytes());
+  password.extend_from_slice(&nfc_passphrase);
+  password.extend_from_slice(&32u64.to_be_bytes());
+  password.extend_from_slice(image_secret);
+  ```
+  Also includes NFC normalization (lines 224-227).
+- **Status:** ✅ **FIXED**
+
+### H2: Master key never zeroized
+
+- **Original claim:** `Vec<u8>` from `derive_master_key` and intermediates leak into heap.
+- **Current state:**
+  - `crypto.rs:212`: returns `Zeroizing<[u8; 32]>`
+  - `crypto.rs:232`: password wrapped in `Zeroizing::new()`
+  - `session.rs` (WASM/CLI): stores keys as `Zeroizing<[u8; 32]>`
+  - CLI rpassword calls wrapped in `Zeroizing::new()`
+- **Note:** JS string zeroization remains a limitation (acknowledged).
+- **Status:** ✅ **FIXED**
+
+### H3: Passphrase strength gate cosmetic
+
+- **Original claim:** Extension accepts any non-empty passphrase; CLI only requires 8 chars.
+- **Current state:**
+  - `setup.ts:152,640`: `score < 3` disables button
+  - `setup.ts:784-789`: server-side re-validation before create
+  - `generators.rs:124-130`: `validate_passphrase_strength()` requires score >= 3
+- **Status:** ✅ **FIXED**
+
+### H4: Git shells out without guards
+
+- **Original claim:** No hooks/gpgsign/editor isolation.
+- **Current state in `helpers.rs:41-55`:**
+  ```rust
+  cmd.args([
+      "-c", "core.hooksPath=/dev/null",
+      "-c", "commit.gpgsign=false", 
+      "-c", "core.editor=true",
+  ]);
+  ```
+  Comment explicitly references "Audit H4".
+- **Status:** ✅ **FIXED**
+
+### H5: WASM Math.random()
+
+- **Original claim:** `lib.rs:240-256` uses `Math.random()` for password generation.
+- **Current state:** `generate_password` calls `core_generate_password` from relicario-core.
+- **generators.rs:**
+  - Line 6: `use rand::rngs::OsRng;`
+  - Lines 61-64: Uses `Uniform::from()` with `OsRng`
+  - No `Math.random()` anywhere in codebase
+- **Status:** ✅ **FIXED**
+
+### H6: Modulo bias
+
+- **Original claim:** `main.rs:308-317` uses `% CHARSET.len()`.
+- **Current state in `generators.rs`:**
+  - Line 61: `let dist = Uniform::from(0..charset.len());`
+  - Line 63: `charset[dist.sample(&mut rng)]` — rejection sampling, no modulo
+- **Status:** ✅ **FIXED**
+
+### H7: rpassword 5.0.1 outdated
+
+- **Original claim:** Uses deprecated `prompt_password_stderr`.
+- **Current state:** `Cargo.toml` shows `rpassword = "7"`, uses `prompt_password`.
+- **Status:** ✅ **FIXED**
+
+### H8: Storage keeps apiToken/imageBase64 plaintext
+
+- **Original claim:** `chrome.storage.local` stores PAT and reference image unencrypted.
+- **Current state:** Still true — `popup-only.ts:139-141` stores `vaultConfig` and `imageBase64`.
+- **Mitigation:** Acknowledged as design constraint; spec documents that filesystem access to browser profile compromises both factors.
+- **Status:** ⚠️ **ACKNOWLEDGED** (not fixed, documented as acceptable tradeoff)
+
+---
+
+## Conclusion
+
+The 2026-04-18 audit identified real vulnerabilities that existed at that time. **All CRITICAL and HIGH findings (C1-C4, H1-H7) have since been remediated** with the exact fixes recommended in the audit. The codebase underwent significant refactoring, making the original line number references obsolete.
+
+H8 remains as an acknowledged design constraint inherent to Chrome extension architecture.
+
+**The audit was accurate and the remediation was thorough.**
--- a/docs/superpowers/audits/2026-05-01-security-audit-opus-4-5.md
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+# Verification: 2026-05-01 Security Audit
+
+**Verified by:** Claude Opus 4.5  
+**Date:** 2026-05-01  
+**Methodology:** Code inspection of referenced file paths and line numbers
+
+---
+
+## Summary
+
+| Finding | File Exists | Lines Accurate | Vulnerability Real | Confidence |
+|---------|-------------|----------------|-------------------|------------|
+| 1 - Backup KDF NFC | ✅ | ✅ | ✅ | 10/10 |
+| 2 - Commit injection | ✅ | ✅ | ✅ | 10/10 |
+| 3 - WASM private key exposure | ✅ | ✅ | ✅ | 10/10 |
+| 4 - Test env vars in prod | ✅ | ✅ | ✅ | 10/10 |
+| 5 - AttachmentId 64-bit | ✅ | ⚠️ off-by-1 | ✅ | 9/10 |
+| 6 - Field history plaintext | ✅ | ✅ | ✅ | 10/10 |
+| 7 - Device keys non-functional | ✅ | ✅ | ✅ | 10/10 |
+| 8 - Path traversal restore | ✅ | ✅ | ✅ | 10/10 |
+
+**Verdict:** All 8 findings are verified as real vulnerabilities in the current codebase.
+
+---
+
+## Finding-by-Finding Verification
+
+### Finding 1 — Backup KDF missing NFC normalization
+
+- **File:** `crates/relicario-core/src/backup.rs`
+- **Claimed lines:** 303-312
+- **Verified:** ✅ `derive_backup_key` at lines 303-312 passes `passphrase` directly to `argon.hash_password_into()` without NFC normalization. Compare to `derive_master_key` in `crypto.rs:224-227` which explicitly normalizes.
+- **Impact confirmed:** Cross-platform restore failure for non-ASCII passphrases.
+
+### Finding 2 — Commit message injection via item titles
+
+- **File:** `crates/relicario-cli/src/main.rs`
+- **Claimed lines:** 565, 899-901, 1110, 1327
+- **Verified:** ✅
+  - Line 565: `format!("add: {} ({})", item.title, item.id.as_str())`
+  - Line 1110: `format!("edit: {} ({})", item.title, item.id.as_str())`
+  - Line 1327: `format!("trash: {} ({})", item.title, item.id.as_str())`
+- **Impact confirmed:** Newlines/control chars in titles corrupt git log output.
+
+### Finding 3 — WASM `generate_device_keypair` crosses private key to JS
+
+- **File:** `crates/relicario-wasm/src/lib.rs`
+- **Claimed lines:** 215-227
+- **Verified:** ✅ Function returns `{ "private_key_base64": "..." }` as `JsValue`, exposing ed25519 private key to JavaScript heap.
+- **Impact confirmed:** Key material accessible to any JS in service worker context.
+
+### Finding 4 — Test env vars ship in production binary
+
+- **File:** `crates/relicario-cli/src/main.rs`
+- **Claimed lines:** 445-446, 421-423, 1425-1426
+- **Verified:** ✅
+  - Lines 421-423: `RELICARIO_TEST_ITEM_SECRET`
+  - Lines 445-446: `RELICARIO_TEST_PASSPHRASE`
+  - Lines 1425-1426: `RELICARIO_TEST_BACKUP_PASSPHRASE`
+- **Impact confirmed:** All checked in production code without `#[cfg(test)]`. Passphrase visible in `/proc/<pid>/environ`.
+
+### Finding 5 — `AttachmentId` truncated to 64 bits
+
+- **File:** `crates/relicario-core/src/ids.rs`
+- **Claimed lines:** 52-57
+- **Actual lines:** 51-56 (off by 1)
+- **Verified:** ✅ `&digest[..8]` = 8 bytes = 64 bits. Birthday collision at ~2³² work.
+- **Impact confirmed:** Attacker with attachment upload can cause silent overwrites.
+
+### Finding 6 — `get_field_history` returns plaintext to JS
+
+- **File:** `crates/relicario-wasm/src/lib.rs`
+- **Claimed lines:** 232-265
+- **Verified:** ✅ Returns historical `Password`/`Concealed` values as plaintext JSON via `v.as_str().to_owned()`.
+- **Impact confirmed:** Password history exposed to JS heap without Zeroizing.
+
+### Finding 7 — Device key system is security theater
+
+- **File:** `crates/relicario-cli/src/main.rs`
+- **Claimed lines:** 2151-2221
+- **Verified:** ✅ `cmd_device()` handles Add/List/Revoke but:
+  - No `sign_commit` or `verify_signature` functions exist anywhere
+  - `devices.json` is plaintext and unauthenticated
+  - Revocation has no enforcement mechanism
+- **Impact confirmed:** Users falsely believe device revocation provides security.
+
+### Finding 8 — Path traversal on backup restore
+
+- **File:** `crates/relicario-cli/src/main.rs`
+- **Claimed lines:** 1619-1626
+- **Verified:** ✅
+  ```rust
+  for item in &unpacked.items {
+      fs::write(target.join("items").join(format!("{}.enc", item.id)), ...)?;
+  }
+  ```
+  `item.id` and `attachment_id` used directly in path construction with no validation.
+- **Impact confirmed:** Crafted `.relbak` with `id = "../../.bashrc"` escapes target directory.
+
+---
+
+## Blockers Assessment
+
+The audit's "Path to Certifiable Safety" section is accurate:
+
+| Blocker | Verified | Severity |
+|---------|----------|----------|
+| B1 - Device key theater | ✅ Real | High |
+| B2 - Backup KDF NFC | ✅ Real | Medium |
+| B3 - Test env vars | ✅ Real | Medium |
+| B4 - Path traversal | ✅ Real | Medium |
+
+All four blockers are confirmed. B1 is the most dangerous as it misleads users about their security posture.
--- a/docs/superpowers/audits/2026-05-01-security-audit.md
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+# Relicario Security Audit — 2026-05-01
+
+Scope: full project audit (not a PR diff). Covers crypto correctness, protocol gaps,
+implementation reality vs. plans, and a roadmap toward third-party auditability.
+
+---
+
+## Section 1 — Security Findings
+
+### Finding 1 — Backup KDF missing NFC normalization
+
+**`crates/relicario-core/src/backup.rs:303-312`** · Severity: **Medium**
+
+`derive_backup_key` passes raw passphrase bytes to Argon2id. The main vault KDF in
+`crypto.rs` uses `u64_be(len) || nfc_passphrase || u64_be(32) || image_secret`. The
+backup KDF has neither NFC normalization nor the length-prefix construction.
+
+**Exploit:** User creates a backup on macOS (NFD normalization) and restores on Linux
+(NFC). The Argon2id input differs → wrong key → unrestorable backup. Affects any
+non-ASCII passphrase (`"Crêpe-7"`, `"café"`, accented chars).
+
+**Fix:** Factor out `normalize_passphrase()` and use it in both `derive_master_key` and
+`derive_backup_key`.
+
+---
+
+### Finding 2 — Commit message injection via item titles
+
+**`crates/relicario-cli/src/main.rs:565, 899-901, 1110, 1327`** · Severity: **Medium**
+
+Item titles (arbitrary user UTF-8) are embedded directly into `-m` commit message strings
+via `format!("add: {} ({})", item.title, ...)`. `git_command` uses `Command::args()` (no
+shell), so shell injection into `git add` is blocked — but newlines in titles produce
+malformed multi-line commit messages that corrupt git log parsers.
+
+**Fix:** Strip control characters from titles before embedding in commit messages, or omit
+the title from the `-m` format entirely and use only the item ID.
+
+---
+
+### Finding 3 — WASM `generate_device_keypair` crosses private key bytes to JS
+
+**`crates/relicario-wasm/src/lib.rs:215-227`** · Severity: **Medium**
+
+Returns `{ "private_key_base64": "..." }` as a `JsValue`. The ed25519 private key lives in
+the JS heap with no `Zeroizing` protection. The vault master key is protected behind an
+opaque `SessionHandle` and never crosses to JS — the device key has no such protection.
+
+**Exploit:** Any JS running in the extension service worker context (compromised dependency,
+content script escalation) that can intercept the return value gets the raw device key.
+
+**Fix:** Never return the private key to JS. Expose only a `sign(handle, data) → signature`
+API; perform the signing in Rust.
+
+---
+
+### Finding 4 — Test env vars ship in production binary
+
+**`crates/relicario-cli/src/main.rs:445-446, 421-423, 1425-1426`** · Severity: **Medium**
+
+`RELICARIO_TEST_PASSPHRASE`, `RELICARIO_TEST_ITEM_SECRET`, `RELICARIO_TEST_BACKUP_PASSPHRASE`
+are checked in production code (not `#[cfg(test)]`). When set, they bypass the interactive
+TTY prompt.
+
+**Exploit:** On Linux, `/proc/<pid>/environ` exposes the passphrase in cleartext to
+same-UID processes. Shell history captures `RELICARIO_TEST_PASSPHRASE=mysecret relicario unlock ...`.
+
+**Fix:** Gate behind `#[cfg(test)]` or a `--features testing` build profile.
+
+---
+
+### Finding 5 — `AttachmentId` truncated to 64 bits of SHA-256
+
+**`crates/relicario-core/src/ids.rs:52-57`** · Severity: **Medium**
+
+`AttachmentId::from_plaintext` takes `&digest[..8]` (8 bytes = 64 bits). Standard
+content-addressed stores use ≥128 bits. With 64 bits, an attacker who can supply attachment
+content can find a second-preimage collision with ~2^32 work, causing a crafted attachment
+to silently overwrite an existing one on disk.
+
+**Fix:** Change `&digest[..8]` → `&digest[..16]` (128 bits). No migration needed for
+existing vaults since only new attachments are affected.
+
+---
+
+### Finding 6 — `get_field_history` re-parses item JSON from JS heap
+
+**`crates/relicario-wasm/src/lib.rs:232-265`** · Severity: **Medium**
+
+Returns all historical `Password`/`Concealed` values as plaintext `JsValue`. The values
+are regular `String` allocations with no `Zeroizing` wrapper before serialization into
+`serde_json::Value`.
+
+**Fix:** Architectural — document that the caller must treat the return value as sensitive.
+For strong hygiene: do all history display in Rust, never returning password history bytes
+to JS.
+
+---
+
+### Finding 7 — Device key system is non-functional as a security control
+
+**`crates/relicario-cli/src/main.rs:2151-2221`** · Severity: **High**
+
+`device add/list/revoke` and `generate_device_keypair` exist, but **no code anywhere signs
+git commits with device keys**, and **no code verifies device signatures**. `devices.json`
+is plaintext in the repo and unauthenticated by the vault.
+
+**Exploit:** Users believe "device revocation" prevents unauthorized access after a device
+is stolen/compromised. It does nothing. A stolen device continues to have full vault access
+via its git remote credentials regardless of revocation.
+
+**Fix:** Either (a) implement commit signing + server-side pre-receive hook verification, or
+(b) remove the `device` subcommands and document that access control is SSH-key-level only.
+
+---
+
+### Finding 8 — Path traversal on backup restore
+
+**`crates/relicario-cli/src/main.rs:1619-1626`** · Severity: **Medium**
+
+During restore, item/attachment IDs from the decrypted backup JSON are used directly as
+path components with no format validation. IDs are AEAD-authenticated but a user restoring
+from a crafted `.relbak` with a known passphrase would execute arbitrary path writes.
+
+**Exploit (social engineering):** Attacker provides a `.relbak` with item ID
+`../../.bashrc` → restore overwrites `~/.bashrc`.
+
+**Fix:**
+```rust
+ensure!(id.len() == 16 && id.chars().all(|c| c.is_ascii_hexdigit()),
+    "invalid id in backup");
+```
+
+---
+
+## Section 2 — Implementation Status
+
+| Feature | Status | Notes |
+|---|---|---|
+| Two-factor decrypt (passphrase + image_secret) | ✅ Implemented | Full crypto pipeline, NFC passphrase, Argon2id m=64MiB t=3 p=4 |
+| imgsecret embed | ✅ Implemented | DCT QIM, QUANT_STEP=50, central 70%, 5-50 redundant copies |
+| imgsecret extract + crop recovery | ✅ Implemented | Majority voting ≥60%, 4 crop search strategies |
+| Manifest browse (schema v2) | ✅ Implemented | Encrypted with master key, search(), title/type/tags/icon |
+| Vault CRUD (init/add/edit/rm/trash/restore/purge) | ✅ Implemented | All 7 item types fully handled |
+| CLI `init` | ✅ Implemented | zxcvbn ≥3 gate, image embed, Argon2id params, git init |
+| CLI `add` / `edit` | ✅ Implemented | All 7 types, TOTP QR decode via rqrr, field history capture |
+| CLI `generate` | ✅ Implemented | Random (rejection-sampled) + BIP39, uses vault defaults |
+| CLI `sync` | ✅ Implemented | `git pull --rebase && git push` |
+| CLI `backup export/restore` | ✅ Implemented | Plan 3A: zstd+AEAD container, optional image + git bundle |
+| CLI `import lastpass` | ✅ Implemented | Plan 3B: CSV validation, Login + SecureNote + TOTP mapping |
+| WASM bindings (all item/manifest/settings) | ✅ Implemented | Complete symmetric set |
+| WASM session handle (opaque master key) | ✅ Implemented | Key never crosses WASM boundary |
+| WASM attachment, generator, TOTP, backup, import | ✅ Implemented | All wired |
+| Field history tracking + CLI `history` | ✅ Implemented | Password/Concealed/TOTP history, prune policies |
+| Trash + retention | ✅ Implemented | `trash list/empty`, TrashRetention window |
+| Attachments (CLI + WASM) | ✅ Implemented | File-level AEAD, cap enforcement, Document type |
+| Settings / VaultSettings | ✅ Implemented | All retention + generator + cap fields, CLI subcommands |
+| Device keys (add/list/revoke) | ⚠️ Partial | Key gen + persistence only — **no signing, no verification** (Finding 7) |
+| Per-vault total attachment cap | ⚠️ Partial | Cap defined in settings, per-attachment enforced — per-vault total bytes not checked |
+| Browser extension UI | ⚠️ Partial | WASM surface complete; extension TypeScript/HTML is a separate repo |
+| Recovery QR | ❌ Plan-only | Spec written; no `recovery_qr.rs` module exists |
+| Password coloring | ❌ Plan-only | Spec written; no implementation |
+| Passphrase rotation | ❌ Deferred | Explicitly back-burnered |
+| Pre-v0.3.0 audit walk | ❌ Not started | Listed as pending before v0.3.0 tag |
+| HOTP counter persistence | ❌ Bug | `Hotp { counter }` never incremented/saved — HOTP desynchronizes immediately |
+
+---
+
+## Section 3 — Path to Certifiable Safety
+
+### Blockers — must fix before any real use
+
+| # | Item |
+|---|---|
+| B1 | **Device key system is security theater** — implement signing or remove the commands. This is the most dangerous finding because it misleads users about their security posture. |
+| B2 | **Backup KDF NFC normalization** — one-line fix; data loss risk for non-ASCII passphrases. |
+| B3 | **Test env vars in production binary** — gate with `#[cfg(test)]`. Exposes passphrase via `/proc`. |
+| B4 | **Path traversal on restore** — two-line ID validation before any `fs::write`. |
+
+### Important — fix before third-party audit
+
+| # | Item |
+|---|---|
+| I1 | Sanitize item titles before embedding in commit messages |
+| I2 | `AttachmentId`: `&digest[..8]` → `&digest[..16]` (128-bit collision resistance) |
+| I3 | Enforce per-vault total attachment bytes cap (already defined, never checked) |
+| I4 | Document manifest integrity model: AEAD protects against silent modification, but item deletion is only detectable via git history |
+| I5 | Stop crossing device private key bytes to JS (prerequisite for B1 if signing is implemented) |
+| I6 | Fix HOTP counter: increment + re-save on each `totp get`, or disable HOTP and return an error |
+
+### Nice-to-have — audit-friendliness
+
+| # | Item |
+|---|---|
+| N1 | Wrap `nfc_passphrase: Vec<u8>` in `Zeroizing` in `derive_master_key` |
+| N2 | `cargo audit` in CI |
+| N3 | Validate Argon2id params on vault load — warn if below production minimums |
+| N4 | Broaden steganography recompression tests to use ImageMagick/libjpeg-turbo (not just the `image` crate) |
+| N5 | Consider machine-readable audit log encrypted alongside the vault |